In general, a passenger compartment of a vehicle such as an automobile is relatively small, and becomes a closed space when windows are closed. The temperature inside the passenger compartment is easily affected by an ambient condition, such as the weather. For example, when a vehicle is parked in sunlight, such as in summer, the temperature of the passenger compartment is abnormally raised by heat ray entering through window glasses. An ordinary air conditioning unit for a vehicle is a central type unit and is designed to air-condition a whole space of the passenger compartment. Therefore, it is likely to take time to control the temperature by such an air conditioning unit.
For example, Japanese Unexamined Patent Publication JP-2006-131106A describes mounting a local air conditioning unit in a seat and to discharge air-conditioned air whose temperature is adjusted from blowoff ports formed in a headrest and an armrest, thereby to air-condition the interior of a passenger compartment. Moreover, JP-2006-131106A describes mounting a Peltier module in a seatback or a seat cushion and transferring heat generated by the Peltier module to a seat surface through a heat conductive sheet.
Also, in a local air conditioning unit described in Japanese Unexamined Patent Publication JP-2002-233431A, a fan is mounted in a seat for generating a flow of air toward a Peltier module. The air blown by the fan is conditioned through the Peltier module and is blown off from a seat surface.